engine: Read "vlanid" and "interface" from VLAN information

If vsdm reports vlanid as an independent field the engine should use it
instead of deducing it from vlan name.

Change-Id: I282c2db9a0fd023ac39fac157ce1c0178800d3af
Bug-Url: https://bugzilla.redhat.com/1091863
Bug-Url: https://bugzilla.redhat.com/999975
Signed-off-by: Alona Kaplan <alkaplan@redhat.com>